Sewerage Treatment Works Upgrade Highworth Wiltshire

Archaeological Watching Brief

for Costain Limited and Atkins Limited

on behalf of Thames Water Utilities Ltd

CA Project: 5686 CA Report: 15854

January 2016

Sewerage Treatment Works Upgrade Highworth Wiltshire

Archaeological Watching Brief

CA Project: 5686 CA Report: 15854

Document Control Grid Revision Date Author Checked by Status Reasons for Approved revision by A 08/12/2015 Paolo Steven Internal Cliff Guarino Sheldon review Bateman

This report is confidential to the client. Cotswold Archaeology accepts no responsibility or liability to any third party to whom this report, or any part of it, is made known. Any such party relies upon this report entirely at their own risk. No part of this report may be reproduced by any means without permission.

CONTENTS

SUMMARY ...... 2

1. INTRODUCTION ...... 3

2. ARCHAEOLOGICAL BACKGROUND ...... 3

3. AIMS AND OBJECTIVES ...... 4

4. METHODOLOGY ...... 4

5. RESULTS (FIG. 2) ...... 5

6. DISCUSSION ...... 5

7. CA PROJECT TEAM ...... 6

8. REFERENCES ...... 6

APPENDIX A: CONTEXT DESCRIPTIONS ...... 7

APPENDIX B: OASIS REPORT FORM...... 8

LIST OF ILLUSTRATIONS Fig. 1 Site location plan (1:25,000) Fig. 2 The site, showing location of groundworks (1:2000)

1 © Cotswold Archaeology Sewerage Treatment Works Upgrade, Highworth, Wiltshire: Archaeological Watching Brief

SUMMARY

Project Name: Sewerage Treatment Works Upgrade Location: Highworth, Wiltshire NGR: SU 19887 93472 Type: Watching Brief Date: 17 November–2 December 2015 Location of Archive: Swindon Museum & Art Gallery Accession Number: SWIMG: 2015.077 Site Code: STWU15

An archaeological watching brief was undertaken by Cotswold Archaeology during groundworks associated with the upgrading of the existing sewerage treatment works at Highworth Wiltshire.

No features or deposits of archaeological interest were observed during the groundworks, and no artefactual material was recovered.

2 © Cotswold Archaeology Sewerage Treatment Works Upgrade, Highworth, Wiltshire: Archaeological Watching Brief

1. INTRODUCTION

1.1 Between November and December 2015 Cotswold Archaeology (CA) carried out an archaeological watching brief for Costain Limited and Atkins Limited, on behalf of Thames Water Utilities Ltd, at Highworth Sewerage Treatment Works (STW), Highworth, Wiltshire (centred NGR: SU 19887 93472; Fig. 1).

1.2 The watching brief was undertaken following consultation with Melanie Pomeroy- Kellinger, County Archaeologist, Wiltshire County Council (WCC). It was carried out in accordance with a subsequent detailed Written Scheme of Investigation (WSI) produced by CA (CA 2015) and approved by Melanie Pomeroy-Kellinger. The fieldwork also followed Standard and guidance: Archaeological watching brief (CIfA 2014).

The site

1.3 The proposed development area is approximately 1.88ha in extent and is contained within the existing STW. The site is bounded by the Blackworth Industrial Estate to the north, Pentylands Lane to the west, residential properties to the south and farmland to the east. The site lies at approximately 83m AOD and is broadly level.

1.4 The underlying bedrock geology of the area is mapped as Oxford Clay Formation Mudstone of the Jurassic period (BGS 2015). The natural substrate, comprising clay, was encountered in the north-eastern part of the site. In south-western part of the site the natural substrate was not revealed due to the limited depth of the groundworks undertaken.

2. ARCHAEOLOGICAL BACKGROUND

2.1 The site has not been subject to previous archaeological assessment, although Highworth itself has been subject to archaeological assessment (WCAS 2004). The following is a summary of publically available information pertinent to the site:

2.2 No prehistoric finds or features are recorded within the site. However, a small number of isolated prehistoric finds are noted within the immediate area. These comprise a Mesolithic flint core c. 600m to the east of the site and a Bronze Age

3 © Cotswold Archaeology Sewerage Treatment Works Upgrade, Highworth, Wiltshire: Archaeological Watching Brief

arrowhead and worked flint flakes c. 500m to the south-east of the site (WCAS 2004).

2.3 A number of Roman sites have been identified in the immediate vicinity. These include an area of Roman settlement identified during the 1970s, c. 200m to the north of the site, and the remains of four Romano-British buildings excavated in 1980 c. 400m to the south of the site (WCAS 2004).

2.4 Two archaeological trench evaluations have been conducted in the immediate vicinity of the site during development at the Blackworth Industrial Estate. An undated pit and an irregular linear slot were excavated during an evaluation in 1999 (Foundations Archaeology 1999). A second archaeological evaluation identified no archaeological features or deposits (CAT 1999).

3. AIMS AND OBJECTIVES

3.1 The objectives of the archaeological works were:

 to monitor groundworks, and to identify, investigate and record all significant buried archaeological deposits revealed on the site during the course of the development groundworks;

 at the conclusion of the project, to produce an integrated archive for the project work and a report setting out the results of the project and the archaeological conclusions that can be drawn from the recorded data.

4. METHODOLOGY

4.1 The fieldwork followed the methodology set out within the WSI (CA 2015). An archaeologist was present during intrusive groundworks (see Fig. 2 for location and extent) comprising:

Area 1: a topsoil strip to enable the construction of a temporary car park Area 2: a topsoil strip to enable the siting of temporary offices and welfare facilities Area 3: ground reduction in the location of new storage/processing tanks

4 © Cotswold Archaeology Sewerage Treatment Works Upgrade, Highworth, Wiltshire: Archaeological Watching Brief

Area 4: ground reduction to identify the location of existing services

4.2 The archive from the watching brief is currently held by CA at their offices in Kemble and will be deposited with Swindon Museum & Art Gallery under accession number 2015.077. A summary of information from this project, set out within Appendix B, will be entered onto the OASIS online database of archaeological projects in Britain.

5. RESULTS (FIG. 2)

5.1 Within Areas 1 and 2 subsoil deposits were revealed between 0.45m and 0.5m below the present ground level (bpgl) and were overlain by topsoil. Excavation ceased at the top of these deposits.

5.2 The natural geological substrate was identified within Areas 3 and 4 at a typical depth of 0.7m bpgl. Its surface showed signs of being heavily disturbed in places by modern activity, presumably during the previous development of the STW. No archaeological features or deposits were identified. The natural substrate was sealed by subsoil, typically 0.2m in depth, which was in turn sealed by topsoil.

5.2 No features or deposits of archaeological interest were observed during the groundworks and, despite visual scanning of spoil, no artefactual material was recovered.

6. DISCUSSION

6.1 Despite the archaeological potential of the application area (see archaeological background above), the watching brief identified no archaeological remains within the area of observed groundworks. The absence of archaeological features/deposits in Areas 3 and 4 may indicate that remains associated with previously identified Roman settlement activity to the north and east of the site either do not extend as far as the current site or that they may have been removed during previous development associated with the existing STW. In Areas 1 and 2 it remains possible that archaeological features/deposits survive but were not revealed by the current works due to the depth of excavation undertaken.

5 © Cotswold Archaeology Sewerage Treatment Works Upgrade, Highworth, Wiltshire: Archaeological Watching Brief

7. CA PROJECT TEAM

Fieldwork was undertaken by Paolo Guarino. The report was written by Paolo Guarino. The illustrations were prepared by Leo Heatley. The archive has been compiled by Paolo Guarino, and prepared for deposition by Hazel O’Neill. The project was managed for CA by Steven Sheldon.

8. REFERENCES

BGS (British Geological Survey) 2015 Geology of Britain Viewer http://mapapps.bgs.ac.uk/geologyofbritain/home.html Accessed 16 December 2015

CA (Cotswold Archaeology) 2015 Sewerage Treatment Works Upgrade, Highworth, Wiltshire: Written Scheme of Investigation for an Archaeological Watching Brief.

CAT (Cotswold Archaeological Trust) 1999 Brinkworth Industrial Estate, Highworth, Wiltshire: Archaeological Evaluation, CA Report No. 001148

FA (Foundations Archaeology) 1999 Brinkworth Industrial Estate, Highworth, Wiltshire: Archaeological Evaluation

WCAS (Wiltshire County Archaeology Service) 2004 The Archaeology of Wiltshire’s Towns. An Extensive Urban Survey: Highworth

APPENDIX A: CONTEXT DESCRIPTIONS

Area Context Type Fill of Context Description L (m) W (m) Depth/ No. No. interpretation thickness (m) 1 100 Layer Topsoil Dark grey brown silt clay >61 >10 0.5 1 101 Layer Subsoil Light grey brown clay silt >61 >10 >0.01 2 200 Layer Topsoil Dark grey brown silt clay >26 >14 0.45 2 201 Layer Subsoil Light grey brown clay silt >26 >14 >0.01 3 300 Layer Topsoil Dark grey brown silt clay >120 >23 0.47 3 301 Layer Subsoil Light grey brown clay silt >120 >23 0.23 3 302 Layer Natural Sterile mid blue grey clay >120 >23 >0.2 Substrate 3 303 Fill 304 Fill Mid-dark grey brown sand silt >17 >2 >0.8 with frequent modern concrete, red brick and metal inclusions 3 304 Cut Modern Modern truncation associated >17 >2 >0.8 truncation with construction of previous STW. 4 400 Layer Topsoil Dark grey brown silt clay >44 >11 0.51 4 401 Layer Subsoil Light grey brown clay silt >44 >11 0.19 4 402 Layer Natural Sterile mid blue grey clay >44 >11 >0.5 Substrate 4 403 Fill 404 Fill Mid-dark grey brown sand silt >7 >1.8 >1 with frequent modern concrete, red brick and metal inclusions 4 404 Cut Modern Modern truncation associated >7 >1.8 >1 truncation with construction of previous STW.

APPENDIX B: OASIS REPORT FORM

PROJECT DETAILS

Project Name Sewerage Treatment Works Upgrade, Highworth, Wiltshire Short description An archaeological watching brief was undertaken by Cotswold Archaeology during groundworks associated with the upgrading of the existing sewerage treatment works.

No features or deposits of archaeological interest were observed during groundworks, and no artefactual material was recovered. Project dates 17 November-2 December 2015 Project type Watching Brief Previous work None Future work Unknown PROJECT LOCATION Site Location Sewerage Treatment Works, Highworth, Wiltshire Study area (M2/ha) 1.88ha Site co-ordinates SU 19887 93472 PROJECT CREATORS Name of organisation Cotswold Archaeology Project Design (WSI) originator Cotswold Archaeology Project Manager Steven Sheldon Project Supervisor Paolo Guarino MONUMENT TYPE None SIGNIFICANT FINDS None PROJECT ARCHIVES Intended final location of archive Content

Physical N/A N/A Paper Swindon Museum & Art Trench recording forms, Gallery/SWIMG: 2015.077 digital photographic register Digital Swindon Museum & Art Digital photographs Gallery/SWIMG: 2015.077 BIBLIOGRAPHY

CA (Cotswold Archaeology) 2015 Sewerage Treatment Works, Highworth, Wiltshire: Archaeological Watching Brief. CA typescript report 15854

9 N Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk GLOUCESTERSHIRE e [email protected]

PROJECT TITLE OXFORDSHIRE Sewerage Treatment Works Upgrade

SWINDON Highworth, Wiltshire

FIGURE TITLE WEST BERKSHIRE Site location plan 0 1km WILTSHIRE FIGURE NO. Reproduced from the 2015 Ordnance Survey Explorer map with DRAWN BY LJH PROJECT NO. 5686 the permission of Ordnance Survey on behalf of The Controller CHECKED BY DJB DATE 18/12/15 of Her Majesty's Stationery Office c Crown copyright Cotswold Archaeology Ltd 100002109 APPROVED BY SS SCALE@A4 1:25,000 1 198 199 200

BLACKWORTH

936 Area 4

Sewage Area 3 Works

PENTYLANDS LN

935

934

Area 1

Area 2 933

N Andover 01264 347630 Cirencester 01285 771022 Exeter 01392 826185 Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected] site boundary PROJECT TITLE Sewerage Treatment Works Upgrade area of observed groundworks Highworth, Wiltshire

FIGURE TITLE The site, showing location of groundworks

DRAWN BY LJH PROJECT NO. 5686 FIGURE NO. Reproduced from the Ordnance Survey 2015 mapping with the permission of 0 100m CHECKED BY DJB DATE 18/12/2015 Ordnance Survey on behalf of The Controller of Her Majesty's Stationery Office APPROVED BY SS SCALE@A3 1:2000 &URZQFRS\ULJKW&RWVZROG$UFKDHRORJ\/WG 2 P:\5686 Sewerage Upgrade, Highworth WB\Illustration\Drafts\5686_Sewerage Treatment Works_Highworth_Fig2.dwg